Feed regulating mechanisms for sewing machines



March 3, 1959 B P. P'lNKvoss 2,875,716

FEED REGULATING MECHNSMS FOR SEWING MACHINES Filed July 27, 1955 2Sheets-Sheet 1 45 72 l` 7o q; l gay 50 i 'flo 2 i i l 11h/h I 4 I5 22 @j2|v I' 'V --24 I8 o I4 Y f 23 I l INVENTR Bertha/dj? Pinkvoss7 Deceasedv Agnes PnkvOSs, Execufrx WITNESS March 3, 1959 BJP. PINKvoss 2,875,716

FEED REGULATING MECHANISMS FOR SEWING MACHINES 2 Sheets-Sheet 2 FiledJuly 27, 1955 INVENTR Bertha/d l? Pin/rvoss, Deceased Agnes Pinkvoss,Execufrix WITNESS BY W AQJU w 7 g 7 ATT0RNE'V United States -Patent YOFEED REGULATING MECHANISMS FOR SEWING MACHINES Berthold I. Pinkvoss,deceased, late of Stratford, Conn.,

by Agnes Pinkvoss, cxecutrix, Stratford, Conn., assignor to The SingerManufacturing Company, Elizabeth, N. J., a corporation of New JerseyApplication July 27, 1955, Serial No. 524,774

1 Claim. (Cl. 112211) lnism for readily and conveniently varying thediameter `of a pulley which is arranged to actuate a belt driven toproller feed member of a sewing machine.

With the above and other objects and advantages in view as willhereinafter appear, this invention comprises the devices, combinations,and arrangements of parts hereinafter described and illustrated in theaccompanying drawings of a preferred embodiment in which:

Fig. 1 is a vertical cross sectional view of a sewing machine having thefeed regulating mechanism of this invention applied thereto.

Fig. 2 is an enlarged cross sectional view of the variable diameterpulley mechanism taken substantially along line 2-2 of Fig. 1.

Fig. 3 represents an exploded perspective view of the variable diameterpulley mechanism of Figs. l and 2.

Referring to the drawings, the invention is illustrated in Fig. 1 asapplied to a sewing machine having a work supporting post 11 mountedupon a machine bed 12 which also carries a pedestal 13 surmounted by abracket arm 14 which terminates in a sewing head 15 overlying the post11. The sewing machine illustrated in Fig. l is constructed and arrangedsubstantially in accordance with U. S. patent of Pinkvoss, No.2,678,010, May 1l, 1954, to which reference may be had for a generaldescription thereof. The present invention concerns a regulatingmechanism for the work feeding instrumentalities of the sewing machinewhich comprise a lower feed wheel 16 journaled in the work supportingpost 11, and a driven top roller feed member 17 journaled in a bracket18 carried by the conventional presser bar (not shown) of the sewingmachine.

A main drive shaft 20 journaled in the backet arm carries a hand wheelpulley 21 and is tted with conventional driving connections in thesewing head for reciprocating a needle bar 22 carrying a needle 23. Bymeans of a clip belt 24 rotary motion is transmitted from the main driveshaft 20 to a bed shaft 25 which is geared, as described in detail inthe above referenced patent, to a hook shaft 26 journaled vertically inthe post 11 and carrying at its upper extremity a rotary hook 27 adaptedto cooperate with the needle 23 in the formation of lock stitches.

The feed wheel 16 is carried in the post 11 by means of a verticallyadjustable bracket 30 and has formed as a part thereof bevel-gear teeth31 disposed in mesh with a pinion 32 fast on the upper part 33 of a feedshaft Aice journaled vertically in a sleeve bushing 34 in the post 11. Auniversal connection 35 is provided between the upper part 33 and alower portion 36 of the feed shaft. A one-way clutch device 37 of thetype disclosed in the U. S. patent of Hacklander, No. 2,277,971, iscarried by the lower portion 36 of the feed shaft. This clutch 37 isadapted to be oscillated by means of an actuating arm 38 connected to apitman 39 which embraces an eccentric (not shown) fast on the bed shaft25. Intermittent rotary motion in one direction is transmitted to thefeed wheel 16 by actuation of the clutch 37.

The top roller feed member 17 is drivingly connected with the feed shaftso as to insure synchronism of feed wheel and top roller movements. Thedriving connections include a pulley il fast on the lower poition 36 ofthe feed shaft, a belt ft2 engaging the pulley 41 with a pulley 43 faston the lower extremity of a shaft 44 which is journaled verticallythrough the pedestal 13 and the bracket arm 1li, and a beit 45 which isarranged to engage the top roller 17 and is directed over a pair ofidler rollers i6 to a pulley indicated generally as 47 carried at theupper extremity ofthe vertical shaft d4.

Although the belts Li2 and 45 and the vertical shaft 44 serve tosynchronize movements of the feed wheel and top roller, proper controlof the work fabrics gives rise to a need for control of the relativeextent or magnitude of movement of the work feeding wheels 16 and 17. Itis also pointed out that `the relative extent of work feeding motionbetween the feed members has no single optimum value but changes as thenature of the work changes. Thus, there is no one relationship to whichthe parts could be adjusted or designed to provide which would besatisfactory under all conditions.

In this invention, control of the extent of work feeding motion of thetop roller 17 relative to the feed wheel 16 is obtainable by means ofthe pulley 47 on the vertical shaft 44. The pulley d'7 is constructed soas to provide a compact arrangement of parts, disposed so as to bereadily accessible to the machine operator and arranged to provide amicrometer adjustment of the diameter of the belt-engaging portionthereof so that the extent of feed motion of the top roller may beregulated with respect to that of the feed wheel. Regardless of thecharacter of work being stitched, therefore, the present inventionprovides convenient regulation effective to insure that each of theplies being stitched will be fed at precisely the required rate.

Referring to Figs. 2 and 3, the variable diameter pulley of thisinvention is carried directly upon the upper extremity of the verticalshaft 11i-i and is disposed to surmount a bearing bracket 5d in whichthe upper extremity of the shaft 44 is journaled. Fast on the .shaftdst, as by set screws 51--5l, and contiguous with the bearing bracket 5dis a collar 52 formed with a counterbore 53. Screw threads 54 are formedon the upper extremity of the shaft 44 upon which a diameter regulatingmember 5S is threadedly engaged. The diameter regulating member 55 isformed with a conically shaped lower portion 56 provided with fourevenly spaced slots 57-57 each extending lengthwise of the regulatingmember. Above the conical portion 56, the member S5 is formed withexternal threads 5S and with diametrically opposed screw driver slotsSQL-r9. Endwise movement of the member 55 is limited by the bottom ofthe counterhore in a downward direction and by a locking screw 6ftthreaded into the shaft 44 at the upper end thereof.

The belt engaging portion of the pulley comprises a composite sheavemade up of an assembly of four sector shaped pulley segments 61 arrangedin the form of an annular ring. The inner surface 62 of each of thesegments is tapered to match the angle of the conical portion 56 at themember 55. The outside surface of each of 'geref/1e accommodatingportion 63 and a projecting inclined portion 64, the portions beingseparated by an annular undercut 65 which provides a seat into which anannular spring clip 66 is disposed. The clip 66 serves yieldingly tourge the segments against the conical portion 56 of the diameterregulating member. Each of the segments is, in addition, formed with anaperture 6'7 adapted to receive a pin 68 of which the head portion isslidably arranged in one of the slots 57 of the regulating member so asto key the segments in place and prevent turning of the segmentsrelatively to the regulating member. An annular locking ring 69encircles and engages the projecting inclined portions 64 of thesegments and is retained securely in place by means of a lock nut '70which engages the external threads 58 of the regulating member. VThelocking ring 69 serves to clamp the segments, the diameter regulatingmember and the shaft together for rotation as a unit.

The bracket arm 14 of the sewing machine is tted with a conventional topcover plate '71 formed with an aperture '72 through which protrude thediameter regulatving member 55 and the lock nut 70. The major portion ofthe variable diameter pulley, therefore, is housed within the bracketarm and only those portions to which access is required for effectingthe necessary adjustments are exposed for ready accessibility to thesewing machine operator.

In operation, the belt accommodating segments 61 are locked in positionbetween the collar 52 and the locking ring 69. The position of thesegments against the regulating member 55 determines the diameter of thebelt ac commodating surfaces 63. of the pulley, the lock nut 70 must beloosened to free the segments 61, the diameter regulating member 55 maythen be turned. If the member 55 is turned countern In order to vary thediameter y Y' 'clockwise and moved upwardly on the shaft 44, the springw v clip 66 will cause the segments 61 to shift inwardly thus yieldingforce of the annular spring clip 66 and will thus increase the pulleydiameter. When the proper setting is reached, tightening of the lock nut70 will x the parts in the proper position against accidental movement.

The construction of this inventiom therefore, provides a feed regulatorwhich is readily accessible and convenient to adjust by which amicrometer adjustment may be obtained of the relative extent of feedbetween opposed feed wheels. Regardless of the type of work beingstitched, therefore, the sewing machine may be readied quickly andeasily to advance both the upper and the lower plies at precisely therequired rate past the stitch forming instrumentalities.

Having thus described the nature of the invention, what is claimedherein is:

In a sewing machine having a hollow frame including a work supportassociated with a bed, a standard rising from said bed, and a bracketarm carried by said standard and disposed to overhang said work support,a compound work feeding mechanism comprising a lower work feedinginstrumentality carried by said work support, mech- 'anism actuated bysaid sewing machine for imparting intermittent work feeding motion tosaid lower work feeding instrumentality, an upper work feeding wheelcarried by said bracket arm, a shaft journaled vertically in `saidstandard, positive driving connections between said work feedinginstrumentality and the lower extremity of said shaft, a variablediameter pulley carried at the upper extremity of said shaft, a beltextending between said variable diameter pulley and said upper workfeeding wheel, said variable diameter pulley including an angularlyadjustable diameter regulating member and an angularly adjustablelocking member for said regulating member, said sewing machine bracketarm being formed with an aperture disposed substantially in axialalignment with said shaft through which said regulating and said lockingmembers are disposedito extend outside the sewing machine frame.

References Cited in the le of this patent UNITED STATES PATENTS2,022,115 Howe Nov. 26, 1935 2,325,643 Weis Aug. 3; 1945 2,678,010Pinkvoss May 11, 1954

